He Looks at You
He looks at you a lot. His eyes linger on yours when you're conversing. That indicates he's really concentrating on what you're saying. Also, he gazes at you when he thinks you're not looking. But keep in mind that if you haven't met yet or you're barely acquainted and he's a shy sort, he may look away when you catch him gazing your way. If you smile at him, he'll be encouraged.
He'll lean toward you and soften his posture. This is a sign that he is getting comfortable with you. He'll also want to get closer and start touching you on the arm or back. Do the same if you like him. Note, however, that there are guys who are generally affectionate and may pat a lot of people. A man should reserve his special attention for you.
He laughs at your jokes, even if no one else thinks they're that funny. He also remembers what you say, even the little details. Men usually talk about themselves more than anything else, so when you notice that a guy is doing less of that and wants to know more about you, chances are he's really interested. You might even find out he's talking to his friends about you.
He Lowers His Voice
You notice that he softens his voice and talks more slowly to you, something he doesn't do with anyone else. This doesn't necessarily mean he's relaxed. In fact, if you pay attention, you might see that he may be nervous around you. He may fidget, because he's not in control. You can come to his rescue by getting him to relax. He'll appreciate it and it'll help bring you closer.